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Could Feeding Livestock Hemp Contaminate Food with Cannabis?

ANALYSIS - European scientists and food safety experts have called for more research and information on the risks to consumers of feeding hemp to livestock and poultry.

The scientists are concerned that the feed could result in cannabinoids – the active constituents of cannabis – being found in meat, milk, dairy products and eggs.

The call for more data follows research by the European Food Safety Authority’s Panel on Contaminants in the Food Chain (CONTAM Panel) requested by the European Commission.

The CONTAM Panel was asked for its scientific opinion on the risks for human health related to the presence of tetrahydrocannabinol (THC) in milk and other food of animal origin, in particular delta-9-tetrahydrocannabinol (Δ9-THC), which comes from the hemp plant Cannabis sativa.

The study shows that the delta-9-tetrahydrocannabinol in the fresh plant has up to 90 per cent non-psychoactive elements, but the plant can have up to 60 other active constituents of cannabis.

The report specifically looks into the potential effects of the psychoactive elements of the cannabinoid delta-9-tetrahydrocannabinol.

The panel initially looked at the results of more than 600 studies on cannabinoids from eight countries with 281 being based food and 322 based on feed.

However, the panel said that among all the studies there were few on foods of animal origin - two on samples of cheese and two on meat products – and it said it had to discount the total number of studies as no firm conclusions could be drawn.

It also looked at information from a previous scientific opinion conducted by EFSA’s FEEDAP and analytical data supplied by the European Industrial Hemp Association and the Swiss Federal Food Safety and Veterinary Office, which it said gave clearer information on dietary exposure scenarios.

The CONTAM Panel looked at different scenarios for the presence of delta-9-tetrahydrocannabinol in hemp seed-derived feed materials, the transfer rate from feed to milk, the daily milk yield in litres per cow, the daily feed consumption and the human consumption of milk and dairy products.

The research had shown that although most milk is pasteurised, this would not affect the presence of the cannabinoid.

The research looked at how much could be consumed and the potential effects on both adults and toddlers.

The panel concluded: “There is substantial uncertainty associated with the exposure estimates obtained under the different scenarios.

“This uncertainty is mainly due to the limited number of available analytical data on delta-9-tetrahydrocannabinol, and the lack of information on the fate of delta-9-tetrahydrocannabinol and its precursor acids in the rumen of the cow and during food processing.

“Dietary exposure to delta-9-tetrahydrocannabinol via consumption of animal tissues and eggs could not be estimated, due to a lack of data on the potential transfer and fate of delta-9-tetrahydrocannabinol.”

However, other experiments on the effects of cannabinoids on animals shows that when eaten delta-9-tetrahydrocannabinol is absorbed slowly into the gastrointestinal tract and it studies showed the carcinogenic qualities of delta-9-tetrahydrocannabinol on mice.

The report said that in dairy cows, the limited data indicated that the transfer rate of delta-9-tetrahydrocannabinol to milk is in the range of 0.10–0.15 per cent but there were no appropriate studies to show a transfer rate into other animal products.

The panel added that the data from these studies was limited and insufficient to draw hard conclusions.

At present two countries in Europe have regulations covering the presence of hemp in food. In Belgium any food containing hemp have to have an exemption from Belgian food regulations and Switzerland lays down maximum levels for specific foods.

In the EU, the production of numerous basic and certified hemp seeds is granted provided specific requirements are fulfilled and the regulations list those feed materials that can be used in animal nutrition (hemp seeds, hemp expeller and hemp oil) provided the tetrahydrocannabinol content complies with EU Legislation.

Except for the maximum content of tetrahydrocannabinol in hemp granted for the production of feed, no other harmonised maximum levels for tetrahydrocannabinol in feed exist in the EU.

The study says there are no specific guidelines for sampling and testing of foods for delta-9-tetrahydrocannabinol.

The CONTAM Panel recommended that analytical methods for the analysis of hemp plants and hemp derived products should be implemented to differentiate between the psychoactive compound delta-9-tetrahydrocannabinol and their non-psychoactive precursor acids.

“Data on the occurrence of delta-9-tetrahydrocannabinol, its precursors and other cannabinoids in hemp-derived feed materials for food-producing livestock are needed,” the panel said.

“Further studies on the transfer rate of delta-9-tetrahydrocannabinol, its metabolites, as well as other cannabinoids, and in particular on those that are known to be psychoactive, into animal products intended for human consumption are needed.

“More information is also needed on the fate of delta-9-tetrahydrocannabinol and its precursor acids in food-producing animals, especially ruminants, and in food processing.

“Data on occurrence of cannabinoids in food, in particular on those that are known to be psychoactive, and those that have the potential to interact with delta-9-tetrahydrocannabinol are needed.”